Screen apparatus



E. J. TAYLOR-SMITH SCREEN APPARATUS 5 Sheets-Sheet l mm, m5 Q NQ 1m my W1 o o R y. l m

mw o MJ v Nov. 15, 1966 Filed March 23, 1964 Nov. 15, 1966 E. JTAYLOR-SMITH SCREEN APPARATUS 5 Sheets-Sheet 2 Filed March 23, 1964INvzNron ERNEST J. mYLOR-SMITH ATTO NEYG NW- 15 1966 E.J.' TAYLOR-SMITH3,285,413

SCREEN APPARATUS Filed March 25, 1964 5 Sheeis-Sheet 5 lNVENTOR gl/ j lA ERNEST 1; TAYLOR-sMl'rH United States Patent Office 3,285,413 PatentedNov. 15, 1966 3,285,413 SCREEN APPARATUS Ernest J. Taylor-Smith,Vancouver, British Columbia,

Canada, assignor to Selectors Aggregates Co. Ltd.,

Vancouver, British Columbia, Canada, a corporation of British Columbia,Canada Filed Mar. 23, 1964, Ser. No. 354,036 11 Claims. (Cl. 209-315)This invention relates to screen apparatus for screening material suchas gravel, crushed rock Iand the like, and has for its particularpurpose the object of producing, from an agglomerate mass of material,ranging from ne to coarse and in which elongated particles commonlycalled shards are found, particles of substantially uniform size andshape. In the specication and claims hereinafter the word shape shall bedeemed to define particles having relatively the same length, breadthand width as opposed to those particles hereinafter called shards,having one dimension, elongated.

It is appreciated that certain apparatus has hereinbefore been designedto produce the material above specilied. However, such apparatus,usually of the vibratory incline screen type, has limits imposed thereonrelative -to the degree of inclination of the screen and upon the periodand amplitude of vibration thereof. These limiting factors in turn limitthe production of the machines and are not suitable for use with alltypes of material. The eiciency of machines hereinbefore has also been4reduced by the moisture present in the material to be screened, theproportion of fines to coarse and the relative densities of the materialhandled. The present screen apparatus Ialso being of the inclinedvibratory type overcomes the objections heretofore mentioned byproviding a means whereby shards are automatically and positivelyrejected independently of the degree yof inclination of the apparatus orupon the period of amplitude of the vibration thereof. The presentmachine is also not limited by the water content of the material treatednor of the relative densities of the individual particles making up themass. The capacity of the present apparatus is therefore limited only byits over-all size.

The present invention comprises an inclined vibratory screen arranged toreceive the material at its upper end, said screen having particlepassing apertures of uniform dimension, ejector means comprising aplurality of particle engaging surfaces arranged below and`substantially parallel with the screen so that one of said surfaceslies directly fbelow to `a corresponding aperture, each of said surfacesbeing spaced below said screen a distance substantially equal to theaperture dimension, means to actuate the ejector means in a directionnormal to the plane of the screen to thereby eject upwardly onto thesurface of the screen shards having one dimension greater than theaperture dimension as said shards attempt to pass through the apertures,and a second inclined vibratory screen arranged below the ejector screento receive material passed by the first vertical screen, said secondscreen having apertures of smaller dimension than said rs-t-rnentionedscreen.

Referring to the drawings which illustrate the embodi- -ments of theinvention,

FIGURE 1 is a plan View of the apparatus in which certain elementsthereof are partially cut away,

FIGURE?. is a side elevation of the apparatus in which certain elementsthereof have -been cut away,

FIGURE 3 is a section taken along line 3 3 of FIG- URE 1,

FIGURE 4 is a fragmentary section showing the disposition of the screenelements of the apparatus, and

FIGURE 5 is a diagrammatic representa-tion of the apparatus in elevationshowing the ow of material thereover.

Referring to the drawings, the apparatus generally numbered 1()`comprises a pair of longitudinal side members 12, to each of `which apair of upright supporting members 15 are secured centrally thereof,said members being mounted in an inclined position on transversestringers 16. Mounted on the top lof the upright supports 15 are a pai-rof bearing blocks 18 which rotatably support a transverse shaft 19, thecentral portion 21 of which is eccentric to the yaxis of rotation ofsaid shaft, the latter having a pulley 23 iixedly secured at one endthereof.

A pair of bearing blocks 25 similar to bearing blocks 18 are mountedbelow the latter on side members 12 to rotatably support a transverseshaft 27 also having a central portion 28 eccentric to the rotationalaxis of the latter much in the same manner as has transverse shaft 19.Transverse shaft 27 also has a pulley 29 xedly secured near one endthereof and connected to pulley 23 by a belt 31. Transverse shaft 27 andwith it transverse shaft 19 are driven by a pulley 32 iixedly connectedto the outer end of transverse shaft 27 and driven by a belt 33, thelatter being connected in a suitable manner to any suitable source ofpower, not shown.

Mounted between the upright supports 15 also in an inclined position areoverlapping tandem screens 35 and 36, tandem ejectors 37 and 38, and ascreen 39, said screens and ejectors having a connection, in a manner tobe described hereinafter, to the central portions 21 and 28 of thetransverse shafts 19 and 27, respectively.

Each of the screens 35 and 36 comprises an aperture plate 40, shown incross section in FIGURE 4, the apertures 41 being of uniform shape, thatis, either round or square, and -arranged in spaced rows runninglongitudinally of the apparatus, each of the rows of apertures in screen35 being staggered relative to the apertures in screen 36. Each of saidscreens has formed as an integral part of or secured as by welding tothe underside of the web of the plate lying between said apertures, aplurality of longitudinal triangular shaped ribs 44.

Each of the screens 35 and 36 is mounted at its longitudinal edgesbetween a pair of vertical side panels 46 extending longitudinally ofthe apparatus, said side panels extending above and below the screensand having transverse supports 48 secured between their ends so that'the panels and transverse supports form a rigid frame 49. Ashereinbefore noted, the screens 35 and 36 are mounted in an inclinedtandem position, the lower edge of the, screen 35 overlapping the upperedge of screen y 36, said screens being spaced apart in a verticaldirection as hereinafter specified.

Each of the side panels 46 is provided near each end thereof withoutwardly extending brackets 52 which rest 'upon Vand are supported bythe upper ends of vertical springs 54, the lower ends of these springsresting on seats 55 secured to the side members 12. The side panels 46are also provided near their upper edges and at a point intermediatetheir length with a pair of outwardly extending brackets 56 to which aresecured a` tures.

Frame 60 is also provided with outwardly extending brackets 65 to whichbearing blocks 67 are secured, the latter being rotatably journalled onthe eccentric portion 28 of transverse shaft 27 in much the same manneras bearing blocks 57 are secured on transverse shaft 19. Frame 60 isalso supported on springs 68 much in the same manner as frame 49 issupported on springs 54.

The upper transverse members 64 serve as bases for vertical supports 69,the latter extending upwardly towards the undersides of screens 35 and36 and carry at their upper ends the ejectors 37 and 38. The latter arecomposed of a plurality of parallel spaced bars 72 arranged so that oneof said bars lies below a corresponding row of apertures 41 formed insaid screens. The upper surfaces 73 of said bars are spaced downwardlyfrom the underside of screens 35 and 36, a distance substantially thatof the largest size of particle desired to pass through the screens in amanner as described hereinafter by example.

Secured to the lower transverse member 63 is the screen 39, the latterbeing comprised of a plurality of longitudinally disposed bars 75extending in side by side relationship the full length of the apparatusand spa-ced apart a distance substantially equal to the smallest size ofparticle it is desired to retain as in a manner hereinafter described.

The apparatus is also provided with means such as chutes or aprons, notshown, arranged to receive the discharge of material from the lower endsof screen 36, ejector 38 and screen 39, in a manner known to thoseskilled in the art of the use of the apparatus of this nature in orderthat the material so segregated may be carried to separate bins orpiles.

The arrangement of the parts of apparatus 1t) and their .relationship inrelative size and spacing may be best described with reference to itsuse in screening an agglomerate material such as crushed gravel so as tosegregate therefrom gravel particles of a uniform shape and passing 11/2but not passing 3A inch. To produce material of this nature, theapertures 41 of screens 35 and 36 would be 11/2 inches in diameter ifround and approximately 11/2 if square. The web portion of plate 40lying between each row of apertures would be approximately 2 inches inwidth, the ejector bars 72 which would be approximately 1% inches inwidth, would lie spaced beneath the underside of plate 40 11/2 inchestherefrom, and the triangular ribs 44 would lie approximately 11/2inches away from the outside corners of said ejector bar 72. The screen39 would lie below the ejector bars at least 3 inches and the bars 75thereof would be spaced slightly vless than inch apart. The shafts 19and 27 would be rotatably disposed relative to each other so that theireccentric central portions 21 and 28, respectively, would lie 180 apart,whereby upon said shafts rotatingthe screens 35 and 36 and ejectors 37and 38 and screen 39 would vibrate in opposition.

It will be seen that material deposited upon the upper side of screen 35will, by reason by vibration of the latter, tend to move downwardly overthe latters inclined surface, the smaller particles of uniform shape upto 1%. inches passing downwardly through the apertures 41 and thencedownwardly between the ejector bar 72. A particle of washed gravel whichhas taken the form of shards, that is, in which one dimension thereof isgreatly elongated, will tend to pass endwise downwardly through theaper- However, before the shards having an elongated length greater than11/2 inches can pass fully downwardly through the aperture, it willcontact the ejector bar 72 v,lying therebelow, the vibratory movement ofthe latter 'cking the shards upwardly through the aperture so thatontinuevits flow over screens 35 and 36. The the` ejector bar 72 onshards is clearly illustrated `),R`E4 in which isri'ndicated shards 80attempting downwardly between the apertures 41 of the -i In this figure,it will be seen that if a shard should become jammed in an aperture, theheavy construction of the bar 72, plate 40 and ribs 44, provides a meanswhereby the shards may be broken into pieces small enough to passdownwardly between the ejector bars to screen 39.

The material falling downwardly on screen 39 will therefore containregularly shaped particles having a maximum passing size of 11/2 inches,together with shards whose elongated length is 11/2 inches or less. Ifthe latter shards have a breadth and width of less than 3A inch, theywill tend to pass downwardly through the bars 72 along with the rejectedfines. The material, therefore, retained by screen 39 will be particlesof uniform shape ranging between 11/2 inches passing and 3A inchretained.

In the operation of vibratory screens, it is often found that particlesbecome jammed in the apertures of the screen elements, thus reducingvthe efficiency of the apparatus. In order to reduce the tendency of thevarious screens in the present apparatus from becoming jammed, the bars75 of screen 39 have a gradually reducing taper from their upper totheir lower ends, as indicated in FIGURE 1 of the drawings. The taper isvery slight, tapering from their upper ends to their lower ends so thatthe width of the spaces therebetween increases from 3% inch at saidupper end to approximately 7s of an inch at the lower end.

It will be appreciated that due to relatively wide transverse spacing ofthe apertures 41, a considerable portion of the material to be removedwill pass unscreened over screen 35, however, this portion of thematerial will fall on that portion of screen 36 in line with a row ofapertures 41. All the material passing over both screens will therefore,at one time or another, pass over or through an aperture.

What I claim as my invention is:

1. A screening apparatus for separating, from an agglomerate mass ofmaterial having a percentage of shards, particles having a uniform sizeand shape comprising an inclined vibratory screen arranged to receivethe material at its upper end, said screen having particle passingapertures of uniform dimension, ejector means having a plurality ofspaced particle engaging surfaces arranged below the screen so that eachof said surfaces lies vertically adjacent to a corresponding aperturebelow said screen and in a plane parallel thereto a distancesubstantially equal to the aperture dimension to thereby prevent thepassage through the apertures of shards having one dimensionsubstantially greater than the aperture dimension, said particleengaging surfaces being spaced apart to permit the passage downwardly ofparticles passing through the first screen, means to move the ejectormeans in a direction normal to the plane of the screen to thereby ejectsaid shards upwardly out of said apertures, and a second inclinedvibratory screen arranged below the ejector means to receive materialpassed by the first-mentioned vibratory screen, said second screenhaving apertures of smaller dimension taken transversely to thedirection of flow of material than said apertures of the first-mentionedscreen.

2. A screening apparatus for separating, from an agglomerate mass ofmaterial having a percentage of shards, particles having a uniform sizeand shape comprising a first screen comprising an inclined vibratoryplate arranged to receive the material at its upper end, said platehaving a plurality of apertures of uniform dimension arranged in rowsextending longitudinally of the direction of flow of the material,ejector means having a plurality of particle engaging surfaces arrangedbelow the screen so that each of said surfaces lies vertically adjacentto a corresponding aperture below said screen and in a plane parallelthereto a distance substantially equal to the aperture dimension tothereby prevent the passage through the apertures of shards Ihaving onedimension substantially greater than the aperture dimension, saidparticle engaging surfaces being spaced apart to permit the passagedownwardly of particles passing through the first screen, means to movethe ejector means in a direction normal to the plane of the screen tothereby eject said shards upwardly out of Said apertures, and a secondinclined vibratory screen arranged below the ejector means to receivematerial passed by the first-mentioned vibratory screen, said secondscreen having apertures of smaller dimension taken transversely to thedirection of flow of material than said apertures of the first-mentionedscreen.

3. A screening apparatus for separating, from an agglomerate mass ofmaterial having a percentage of shards, particles having a uniform sizeand shape comprising a rst screen comprising an inclined vibratory platearranged to receive the material at its upper end, said plate having aplurality of apertures of uniform dimension arranged in rows extendinglongitudinally of the direction of How of the material, ejector meanscomprising a plurality of longitudinally extending bars in spaced sideby side relationship so that each bar lies vertically below a row ofapertures in the screen a distance substantially equal to the aperturedimension to thereby prevent the passage through t-he apertures ofshards having one dimension substantially greater than the aperturedimension, said bars being spaced apart to permit the passage downwardlyof particles passing through the rst screen, means to vibrate theejector me-ans in a direction normal to the plane of the screen tothereby eject said shards upwardly lout of said apertures, and a secondinclined vibratory screen arranged `below the ejector means to receiveanaterial passed by the first-mentioned screen, said second screenhaving apertures of la smaller dimention taken transversely to thedirection of flow of material than said apertures of the rst-mentionedscreen.

4. A screening apparatus as claimed in claim 3 in which each of theejector bars is inclined parallel to said rst screen and tapers in widthfrom its upper end to its lower end.

5. A screening apparatus for separating, from an ag glomerate mass ofmaterial having a percentage of shards, particles having a uniform sizeand shape comprising an inclined vibratory screen arranged to receivethe material at its upper end, said screen having particle passingapertures of uniform dimension, ejector means having a plurality ofspaced particle engaging surfaces arrange-d below the screen so thateach of said surfaces lies vertically adjacent to a correspondingaperture below said screen and in a plane parallel thereto a distancesubstantially equal to the aperture dimension to thereby prevent thepassage through the apertures of shards having one dimensionsubstantially greater than the Iaperture dimension, said particleengaging surfaces being spaced apart to permit the passage downwardly ofparticles passing through the first screen, and a second inclinedvibratory screen 'arranged below the ejector to receive material passedby the first-mentioned vibratory screen, said second screen comprising aseries of longitudinally extending bars spaced apart in side by siderelationship a distance less than the aperture dimension of therst-mentioned screen.

6. A screening apparatus as claimed in cl-aim 5 in which each of thebars of the second vibratory screen tapers in width from its upperinclined end to its lower inclined end.

7. A screening apparatus for separating, from an agglomerate mass ofmaterial having a percentage of shards, particles having a uniform sizeand shape comprising a first screen comprising an inclined vibratoryplate arranged to receive the material at its upper end, said platehaving a plurality of apertures of uniform dimension arranged in rowsextending longitudinally of the direction of ow of the material, ejectormeans comprising a plurality of longitudinally extending bars in spacedside by side relationship so that each bar lies vertically below the rowof apertures in the screen a distance substantially equal to theaperture dimension to thereby prevent the passage through the aperturesof shards having one dimension substantially greater than the aperturedimension, said bars being spaced apart to permit the passage downwardlyof particles passing through t-he rst screen, and a second inclinedvibratory screen arranged below the ejector to receive material passedby the first-mentioned vibratory screen, said second screen comprising aseries of longitudinally extending bars spaced apart in side by siderelationship a distance less than the aperture dimension of thefirst-mentioned screen.

8. A screening apparatus as claimed in claim 7 in which each of the barsof the ejector is inclined parallel to said rst screen and tapers inwidth from its upper end to its lower end and in which each of the barsof the second vibratory screen tapers in width from its upper inclinedend to its lower inclined end.

9. A screening apparatus for separating, from an agglomerate mass ofmaterial having a percentage of shards, particles having a uniform sizeand shape comprising a first vibratory screen comprising a pair ofinclined vibratory plates arranged in tandem and descending inoverlapping order, said plates having a plurality of apertures ofuniform dimension arranged in rows extending longi- .tudinally of the-direction of flow of the material thereover, a pair of ejectors, eachcomprising a plurality of longitudinally extending bars in spaced sideby side relationship, each of said bars being spaced vertically below arow of apertures in the plate above and in a plane parallel to the planeof the screen a distance substantially equal to the aperture dimensionto thereby prevent the passage through the apertures of shards havingone dimension substantially greater than the aperture dimension, saidbars being spaced apart to permit the passage downwardly of particlespassing through the rst screen, means to move the ejectors in adirection normal to the plane of the screen to thereby eject saids-hards upwardly out of said apertures, and a second inclined vibratoryscreen arranged below the ejector to receive material passed by thefirst-mentioned screen, said second screen being comprised of a seriesof longitudinally extending bars spaced apart in `side by siderelationship a distance less than the aperture dimension of saidfirst-mentioned screen.

10. A screening apparatus as claimed in claim 9 in which each of therows 0f lapertures in one of the plates of the first-mentioned screenlies `on the projection lof a line bisecting a pair of rows of aperturesin the other of said plates.

11. A screening apparatus as claimed in claim 10 in which each of the-bars of the ejector and said second screen tapers in width from itsupper inclined end to its lower inclined end.

References Cited by the Examiner UNITED STATES PATENTS 424,002 3/ 1890Jones 209-384 HARRY B. THORNTON, Primary Examiner. L. H. EATHERTON,Assistant Examiner.

1. A SCREENING APPARATUS FOR SEPARATING, FROM AN AGGLOMERATE MASS OFMATERIAL HAVING A PERCENTAGE OF SHARDS, PARTICLES HAVING A UNIFROM SIZEAND SHAPE COMPRISING AN INCLUDING VIBRATORY SCREEN ARRANGED TO RECEIVETHE MATERIAL AT ITS UPPER END, SAID SCREEN HAVING PARTICLE PASSINGAPERTURES OF UNIFROM DIMENSION, EJECTOR MEANS HAVING A PLURALITY OFSPACED PARTICLE ENGAGING SURFACES ARRANGED BELOW THE SCREEN SO THAT EACHOF SAID SURFACES LIES VERTICALLY ADJACENT TO A CORRESPONDING APERTUREBELOW SAID SCREEN AND IN A PLANE PARALLEL THERETO A DISTANCESUBSTANTIALLY EQUAL TO THE APERTURE DIMENSION TO THEREBY PREVENT PASSAGETHROUGH THE APERTURES OF SHARDS HAVING ONE DIMENSION, SUBSTANTIALLYGREATER THAN THE APERTURE DIMENSION, SAID PARTICLE ENGAGING SURFACESBEING SPACED APART TO PERMIT THE PASSAGE DOWNWARDLY TO PARTICLES PASSINGTHROUGH THE FIRST SCREEN, MEANS TO MOVE THE EJECTOR MEANS IN A DIRECTIONNORMAL TO THE PLANE OF THE SCREEN TO THEREBY EJECT